The long term objective of this research is to determine whether antibodies to membrane components involved in bacterial calcification can be exhibited as an adjunct to current anti-tarter therapy. This Phase I proposal exploits the availability of a polyclonal antibody to Bacterionema matruchotii proteolipid to assess the validity of this approach in vitro. Inhibition of B. matruchotii calcification in vitro by antibody will be used to determine whether the therapy is effective on growing, dead or lysed cells and when during the life cycle of the bacteria the antibody must be present. Whether antibody generated to B. matruchotii proteolipid can be used to block mineralization in other microorganisms associated with calculus will be tested using Strep. species, two of which calcify in culture and one which does not, and mixed plaque cultures. These studies will indicate the feasibility of using antibodies generated to a bacterial calcification nucleator to prevent or inhibit hydroxyapatite formation in whole cells and in mixed plaque conditions typical of the oral cavity. The data will also suggest whether B. matruchotii proteolipid, specifically,might be an effective Immunogen for stimulating antibody production.